The present invention relates generally to the manufacture of semiconductors and specifically to a process of fabricating low noise polycrystalline silicon resistors.
The manufacture of semiconductors and resistor commonly contains, as one step, an annealing process, as shown in U.S. Pat. No. 3,765,940 issued to Hentzchel on Oct. 16, 1973 and U.S. Pat. No. 3,308,528 issued to Bullard et al on Mar. 14, 1967, the disclosure of which are incorporated by reference.
Polycrystalline silicon (polysilicon) resistors are well known in the art and serve as important elements in some semiconductor imagers and memory chips. However, these resistors produce l/f noise. Most of the theories of l/f noise suggest that this noise originates at interfaces where there are carrier traps.
In view of the foregoing discussion, it is apparent that there currently exists the need of a fabrication process that reduces the noise generated at the interfaces of polysilicon resistors. The present invention is directed towards satisfying that need.